Processors have evolved throughout recent decades by becoming smaller in size, more sophisticated in design and exhibiting faster performance. Such an evolution has resulted for various reasons, one of which is portability of systems incorporating processors. Portability introduces demands on processors such as smaller size, reduced power and efficient performance.
While processors have experienced tremendous advancements, the code or software program used to program them essentially uses the same code as that of its origin. The original PC-based code is referred to as the “x86” instruction code. Thus, the x 86 instruction codes remains the code largely used for programming even in the most advanced processors.
Applications of processors are, for example, in personal computers (PCs), workstations, networking equipment and portable devices. Examples of portable devices include laptops, which are portable PCs, and hand-held devices.
More advanced processors use a sequencer to sequence operations, which are translated from sequences of x86 instructions, to improve throughput and increase performance. However, current sequencing techniques leave room for improvement, as the performance improvement realized thereby does not meet the demands imposed on future processors.
Moreover, power consumption is of vital importance to systems using processors, particularly to portable systems, such as laptops or hand-held electronic devices. While power consumption has been reduced in recent processor designs, nevertheless, a need for further reduction in power consumption remains.
Due to the wide use of code based on the x86 instruction set, particularly by software programmers who have become well accustomed to this code and are not likely to readily adapt to another code, backward compatibility of code is key in the architecture of a new processor. That is, the user of a newly-designed processor must enjoy the ability to use the same code utilized in a previous processor design without experiencing any problems.
In light of the foregoing, there is a need for a processor having a trace unit (or front end) for efficiently and in an improved manner sequencing traces, to be executed by an execution unit (or back end), while improving power consumption and maintaining code backward compatibility.